By way of example, reference can be made to documents FR-A-2 671 461 and FR-A-2 684 471 in the name of the Applicant, which describe a memory card of the above-specified type.
This type of memory card having an integrated circuit embedded in the bulk of the card body is sometimes insufficiently reliable because of the stresses exerted on the edges of the integrated circuit when the card is subjected to bending or flexing. If a high degree of flexing is applied, then the curving of the card body runs the risk of destabilizing retention of the integrated circuit in the card body, and this can go as far as leading to said integrated circuit being expelled. In practice, it is commonplace to cover the conductor pattern, e.g. by means of a varnish that is usually transparent, while leaving the conductive areas of the conductor pattern uncovered. This protective layer participates in holding the integrated circuit in the card body in the event of said card body being flexed, however this holding is of limited effectiveness.
Consequently, there exists a need to improve the retention of an integrated circuit in a card body in order to obtain better resistance to the flexing that may be applied to the card.
This technical problem is already known for laminated cards, i.e. cards of the type comprising a hot-softenable core layer, two covering layers disposed on either side of the core layer, and a module integrated in the core layer and in one of the covering layers by hot-rolling after the various elements making up the card have been stacked on one another. For cards of that type, proposals have thus been made to put into place a belt surrounding the module and extending in the core layer so as to limit the bending forces to which the resin mass constituting the module is subjected, consequently reducing the risk of link members breaking (reference can be made in particular to document WO-A-92/01533 and EP-A-0 466 557).
Nevertheless, it is not possible to use those techniques with an integrated circuit that is embedded directly into the bulk of the card body since it would be quite impossible to place a belt around the integrated circuit.
Proposals have also been made to place a reinforcing plate in the bottom of a housing made in the card body for the purpose of stiffening the zone in which the integrated circuit is installed, as illustrated in document JP-A-61 095 486. Nevertheless, the reinforcement provided thereby is limited since neither the reinforcing plate nor the integrated circuit is embedded directly in the body of the card.
Document EP-A-0 189 039 describes a laminated card in which the integrated card is housed in a recess formed in a hard core disposed in the core layer of the card so as to provide a degree of protection to the integrated circuit when the card is subjected to deformation.
Document EP-A-0 311 434 describes a laminated card having an integrated circuit, in which a reinforcing element in the form of a star is disposed on each of the two faces of the card, on either side of the integrated circuit.
Finally, document EP-A-0 331 316 describes a laminated card in which the integrated circuit is surrounded by a deformable tubular element made of rubber which serves to absorb shocks and deformation when the card is handled.
Furthermore, document EP-A-0 128 822 describes a hot-pressing method of assembling an integrated circuit module in a card body. It should be observed that no reinforcing element is provided in the zone occupied by the integrated circuit.